Effect Of Cardiorespiratory Fitness Research Articles

Effects of cardiorespiratory fitness on changes in secretory immunoglobulin A following a maximal exercise test

Effects of cardiorespiratory fitness on changes in secretory immunoglobulin A following a maximal exercise test

Stroke Incidence in Patients With Hypertension According to Cardiorespiratory Fitness.

Hypertension and physical inactivity are risk factors for stroke. The effect of cardiorespiratory fitness (CRF) on stroke risk in patients with hypertension has not been assessed. We evaluated stroke incidence in patients with hypertension according to CRF and changes in CRF. We included 483 379 patients with hypertension (mean age±SD; 59.4±9.0 years) and no evidence of unstable cardiovascular disease as indicated by a standardized exercise treadmill test. Patients were assigned to 5 age- and sex-specific CRF categories based on peak metabolic equivalents achieved at the initial exercise treadmill test and in 4 categories based on metabolic equivalent changes over time (n=110 576). Multivariable Cox models, adjusted for age, and comorbidities were used to estimate hazard ratios and 95% CIs for stroke risk. During a median follow-up of 10.6 (interquartile range, 6.6-14.6) years, 15 925 patients developed stroke with an average yearly rate of 3.1 events/1000 person-years. Stroke risk declined progressively with higher CRF and was 55% lower for the High-fit individuals (hazard ratio, 0.45 [95% CI, 0.42-0.48]) compared with the Least-fit. Similar associations were observed across the race, sex, and age spectra. Poor CRF was the strongest predictor of stroke risk of all comorbidities studied (hazard ratio, 2.24 [95% CI, 2.10-2.40]). Changes in CRF reflected inverse and proportional changes in stroke risk. Poor CRF carried a greater risk than any of the cardiac risk factors in patients with hypertension, regardless of age, race, or sex. The lower stroke risk associated with improved CRF suggests that increasing physical activity, even later in life, may reduce stroke risk.

Effects of Cardiorespiratory Fitness on Immune Cell Mitochondrial Metabolism in Health and Disease

Problem: Cardiorespiratory fitness (CRF) and mitochondrial function are important factors in health and disease. Even in immune cells, an effective metabolism is crucial for most major cellular functions, such as T-cell proliferation. Little is known about the relationship between CRF and mitochondrial metabolism of immune cells. Methods: In this narrative review, we collected the most recent literature in the field of exercise immunology and mitochondrial immune cell metabolism. We included studies, which used Oxygraph- or Seahorse techniques for measurement of mitochondrial function in various immune cell populations and subtypes associated with topics in the field of exercise in health and disease. Results: 20 studies were included in our analysis. Cell populations were PBMCs (peripheral blood mononuclear **cells), lymphocytes, T cells, NK cells, platelets, and neutrophils. While mitochondrial function was inconstantly affected through acute bouts of exercise, most of the studies, which included training interventions, reported a higher mitochondrial function in immune cells, which were in some studies correlated with the CRF. In various disease conditions, mitochondrial function of immune cells was impaired compared to healthy controls. › Discussion: If a regular exercise training is followed by an improvement in immune cell mitochondrial respiration, regular exercise could become even more important in the context of optimizing immune function and immune regulation in prevention and therapy.

The effect of cardiorespiratory fitness and habitual physical activity on cardiovascular responses to 2 h of uninterrupted sitting.

Prolonged uninterrupted sitting of >3 h has been shown to acutely cause central and peripheral cardiovascular dysfunction. However, individuals rarely sit uninterrupted for >2 h, and the cardiovascular response to this time is currently unknown. In addition, while increased cardiorespiratory fitness (CRF) and habitual physical activity (HPA) are independently associated with improvements in central and peripheral cardiovascular function, it remains unclear whether they influence the response to uninterrupted sitting. This study sought to 1) determine whether 2 h of uninterrupted sitting acutely impairs carotid-femoral pulse wave velocity (cfPWV), femoral ankle PWV (faPWV), and central and peripheral blood pressure and 2) investigate the associations between CRF and HPA versus PWV changes during uninterrupted sitting. Following 2 h of uninterrupted sitting, faPWV significantly increased [mean difference (MD) = 0.26 m·s-1, standard error (SE) = 0.10, P = 0.013] as did diastolic blood pressure (MD = 2.83 mmHg, SE = 1.08, P = 0.014), however, cfPWV did not significantly change. Although our study shows 2 h of uninterrupted sitting significantly impairs faPWV, neither CRF (r = 0.105, P = 0.595) nor HPA (r = -0.228, P = 0.253) was associated with the increases.NEW & NOTEWORTHY We demonstrate that neither cardiorespiratory fitness nor habitual physical activity influence central and peripheral cardiovascular responses to a 2-h bout of uninterrupted sitting in healthy young adults.

Mediation role of cardiorespiratory fitness on association of physical activity and physical literacy among 8-12 years old children: the PAK-IPPL cross-sectional study.

The effect of cardiorespiratory fitness (CRF) on the relationship of physical activity (PA), and physical literacy (PL) in 8-12 Pakistani children are largely unknown. Therefore, this study aims to examine the mediating role of CRF in the relationship between PA and PL in this demographic. This cross-sectional study involved 1,360 children aged 8-12 (mean age = 10.00, SD = 1.41 years) from 85 higher secondary schools in South Punjab, Pakistan. Data were collected during the 2020-2021 academic year using the Canadian Assessment of Physical Literacy-2 (CAPL-2) protocol to assess physical activity (PA), Body Mass Index (BMI), and PL levels. CRF was measured using the PACER (Progressive Aerobic Cardiovascular Endurance Run) test. Descriptive statistics, independent samples t-tests, Chi-squared tests, and Generalized Additive Models for Location, Scale, and Shape (GAMLSS) were used for age and sex-specific CAPL-2 scoring. Associations among components were evaluated through Pearson's correlation, multivariate logistic regression, and mediation analyses. The study revealed that boys had significantly higher scores in CRF, PA, and PL across all age groups compared to girls (p < 0.001), with boys' scores being 20%, 10%, and 14% higher, respectively, than those of girls. Conversely, overweight children showed significantly reduced PA and PL levels (p < 0.001). An inverse correlation was found between BMI and CRF (r 2 linear = 0.022; quadratic = 0.028). CRF scores had significant negative correlations BMI (r = -0.143) and positive associations with MVPA, PA, DB, and PL (r ranging from 0.241 to 0.624). CRF was observed to partially mediate the association between MVPA and PL. The direct impact of PA on PL was significant and meaningful (β = 0.002, p < .001). Additionally, the indirect effect of PA on PL through CRF was also significant (β = 0.001, p < .001), indicating that CRF serves as an important mediator in this relationship. The combined total effect of PA on PL, which includes both direct and mediated pathways, was robust and highly significant (β = 0.003, p < .001). The study revealed a strong positive correlation between CRF, PA, and PL, but a negative one with BMI in South Punjab children aged 8-12. Notably, CRF and PA emerged as significant predictors of PL levels in this population. Consequently, interventions that are both systematic and targeted towards improving these factors should be implemented as strategies to enhance children's PL levels and promote physically active behaviors.

Effects of Cardiorespiratory Fitness on Cardiovascular Disease Risk Factors and Telomere Length by Age and Obesity.

This study investigates differences in telomere length according to obesity, cardiovascular disease (CVD) risk factors, and fitness level in South Korean males. The subjects of this study were males in their 10s to 50s (n=249). We measured obesity indices, CVD risk factors, leukocyte telomere length (LTL), and cardiorespiratory fitness (CRF). Correlation and regression analyses were performed to analyze the data. Measurement of participants' obesity indices, CVD risk factors, and maximum oxygen intake and analyzing their correlations with LTL revealed that LTL and CRF decreased with age and the levels and numbers of obesity indices and CVD risk factors increased. The LTL showed differences according to whether subjects exhibited obesity or dyslipidemia and by CRF level. When all the variables that influence the LTL were adjusted, the LTL became shorter as the age and low-density lipoprotein cholesterol (LDL-C) level increased, and it became longer as the maximum rate of oxygen utilization (VO2max) increased. When the age and CVD risk factors that influence the LTL were adjusted according to obesity and CRF for the obese group, the LTL became shorter as the age and LDL-C level increased (P<0.01), and it became longer as VO2max increased (P<0.01). We found that obesity influenced the LTL by increasing the levels of CVD risk factors and decreasing CRF, whereas maintaining high CRF could alleviate the effects of obesity and CVD risk factors according to age while maintaining and influencing the elongation of LTL.

The effects of cardiorespiratory fitness and ageing on arterial stiffness in athletic older populations

Introduction: Arterial stiffening is a physiological occurrence where there is a decrease in arterial wall compliance, which alters blood pressure and flow. This causes significant aetiological consequences such as hypertension and cardiovascular events, and, as such, arterial stiffness can be used as a subclinical marker for cardiovascular disease. Importantly, arterial stiffness increases in parallel with ageing, even in the absence of disease, thus the prevention of arterial stiffening is of considerable clinical importance for reducing cardiovascular morbidity and mortality.

The Relative Importance of Age at Peak Height Velocity and Fat Mass Index in High-Intensity Interval Training Effect on Cardiorespiratory Fitness in Adolescents: A Randomized Controlled Trial.

Background: This study aimed to evaluate the role of biological age in the relationship between preintervention fat mass and cardiorespiratory fitness effects (CRF) after High-Intensity Interval Training (HIIT) intervention in adolescents. Methods: A total of 141 boys and girls (16 years) were examined as control (CG) and experimental (EG) groups that conducted a 10-week HIIT implemented in physical education. Measurements: body height, body weight, fat mass index (FMI), CRF (Harvard Step Test). Predicted age at peak height velocity (APHV) was calculated. Pathway analyses were conducted to identify the influences of the measured variables. Results: APHV harmed the level of ΔFI (fitness index) (β = −0.270; p = 0.035), while HIIT had a positive effect on changes in ΔFI (β = 0.246; p = 0.002). Sex affected the changes in CRF (β = 0.344; p = 0.011). Two models were designed respective to sex. The effect of the APHV on ΔFI in girls was close to significant (p = 0.053) but was non-significant in boys (p = 0.311). Changes in CRF in girls were positively and close to significance (p < 0.100) affected by FMIbaseline. Conclusion: HIIT is an effective way of exerting positive changes in CRF in adolescents, which is greater in boys than girls. APHV plays a role only in girls. The HIIT should be tailored to girls depending on their maturity status.

The Acute Effects of Single or Repeated Bouts of Vigorous-Intensity Exercise on Insulin and Glucose Metabolism during Postprandial Sedentary Behavior

Fitness and exercise may counteract the detrimental metabolic and mood adaptations during prolonged sitting. This study distinguishes the immediate effects of a single bout vs. work-load and intensity-matched repeated exercise breaks on subjective well-being, blood glucose, and insulin response (analyzed as area under the curve) during sedentary time; and assesses the influence of fitness and caloric intake on metabolic alterations during sedentariness. Eighteen women underwent cardiopulmonary exercise testing and three 4 h sitting interventions: two exercise interventions (70% VO2max, 30 min, cycle ergometer: (1) cycling prior to sitting; (2) sitting interrupted by 5 × 6 min cycling), and one control condition (sitting). Participants consumed one meal with ad libitum quantity (caloric intake), but standardized macronutrient proportion. Exercise breaks (4057 ± 2079 μU/mL·min) reduced insulin values compared to a single bout of exercise (5346 ± 5000 μU/mL·min) and the control condition (6037 ± 3571 μU/mL·min) (p ≤ 0.05). ANCOVA revealed moderating effects of caloric intake (519 ± 211 kilocalories) (p ≤ 0.01), but no effects of cardiorespiratory fitness (41.3 ± 4.2 mL/kg/min). Breaks also led to lower depression, but higher arousal compared to a no exercise control (p ≤ 0.05). Both exercise trials led to decreased agitation (p ≤ 0.05). Exercise prior to sitting led to greater peace of mind during sedentary behavior (p ≤ 0.05). Just being fit or exercising prior to sedentary behavior are not feasible to cope with acute detrimental metabolic changes during sedentary behavior. Exercise breaks reduce the insulin response to a meal. Despite their vigorous intensity, breaks are perceived as positive stimulus. Detrimental metabolic changes during sedentary time could also be minimized by limiting caloric intake.

Effects of Cardiorespiratory Fitness on Cerebral Oxygenation in Healthy Adults: A Systematic Review.

IntroductionExercise is known to improve cognitive functioning and the cardiorespiratory hypothesis suggests that this is due to the relationship between cardiorespiratory fitness (CRF) level and cerebral oxygenation. The purpose of this systematic review is to consolidate findings from functional near-infrared spectroscopy (fNIRS) studies that examined the effect of CRF level on cerebral oxygenation during exercise and cognitive tasks.MethodsMedline, Embase, SPORTDiscus, and Web of Science were systematically searched. Studies categorizing CRF level using direct or estimated measures of V̇O2max and studies measuring cerebral oxygenation using oxyhemoglobin ([HbO2]) and deoxyhemoglobin ([HHb]) were included. Healthy young, middle-aged, and older adults were included whereas patient populations and people with neurological disorders were excluded.ResultsFollowing PRISMA guidelines, 14 studies were retained following abstract and full-text screening. Cycle ergometer or treadmill tests were used as direct measures of CRF, and one study provided an estimated value using a questionnaire. Seven studies examined the effects of CRF on cerebral oxygenation during exercise and the remaining seven evaluated it during cognitive tasks. Increased [HbO2] in the prefrontal cortex (PFC) was observed during cognitive tasks in higher compared to lower fit individuals. Only one study demonstrated increased [HHb] in the higher fit group. Exercise at submaximal intensities revealed increased [HbO2] in the PFC in higher compared to lower fit groups. Greater PFC [HHb] was also observed in long- vs. short-term trained males but not in females. Primary motor cortex (M1) activation did not differ between groups during a static handgrip test but [HHb] increased beyond maximal intensity in a lower compared to higher fit group.ConclusionConsistent with the cardiorespiratory hypothesis, higher fit young, middle-aged, and older adults demonstrated increased cerebral oxygenation compared to lower fit groups. Future research should implement randomized controlled trials to evaluate the effectiveness of interventions that improve CRF and cerebral oxygenation longitudinally.

노인여성의 심폐체력이 일상생활체력에 미치는 영향

The purpose of this study was to examine the cross-sectional changes in cardiorespiratory fitness and daily living fitness according to the aging of elderly women and the effect of cardiorespiratory fitness on daily living fitness. The subjects were 67 elderly women (72.4±5.4 yrs), 65-69 years group (66.3±1.4 yrs, n=23), 70-74 years group (72.7±1.2 yrs, n=20), 75-79 years group (75.9±0.8 yrs, n=14) and over 80 years group (81.5±2.3 yrs, n=10). To measure cardiorespiratory fitness, exercise load test was performed to calculate ˙VOSUB2peak/SUB. For daily living fitness, 10 items related to primary activities such as giggling and housework and secondary activities such as mobility, social activities and health promotion activities were selected. As a result, the cardiorespiratory fitness and daily living fitness factors tended to decrease with age. In particular, it was more pronounced in the group over 80 years group. The relationship between ˙VOSUB2peak/SUB and daily living fitness showed a significant correlation in all items except agility and dynamic equilibrium. In conclusion, elderly people whose cardiorespiratory fitness deteriorates with increasing age can have a negative effect on daily living fitness, and the importance of physical activity to improve or maintain daily living fitness regardless of age is considered.

Effects of cardiorespiratory fitness on cognitive function in middle school students: a systematic review

The purpose of this study is to explore the relationships between cardiorespiratory fitness and cognitive function in middle school students. Methods: An extensive literature search was performed for articles published from March 2011 to March 2021 in PubMed, Web of Science, EBSCO and CNKI (a Chinese database). Studies were included if: (1) the investigated population was aged between 6 and 18 years, (2) they reported the following outcome indicators: VO2max or VO2peak, cognitive function and/or at least one of the following three dimensions: executive function, attention network, intelligence. Studies that did not meet the aforementioned inclusion criteria or that had a study population with pathological obesity or other related diseases were excluded. Forty-nine articles were included, and the information on the relationships between cardiorespiratory fitness and cognitive function was retrieved for the systematic review. Results: As for the relationships between cardiorespiratory fitness and executive function, consistent evidence showed that adolescents with good cardiorespiratory fitness had better executive function. It should be noted that, compared to other variables corresponding to physical fitness, cardiorespiratory fitness is the most important factor of the attention network. Cardiorespiratory fitness was also found to be a mediating variable for the relationships between birth weight and intelligence. Conclusion: In previous studies, cardiorespiratory fitness was found to be related to different dimensions of middle school students’ cognitive function, including executive function, attention network and intelligence. Evidence also indicated that cardiorespiratory fitness was the most important type of physical fitness related to a certain dimension of cognitive function.

Effects of cardiorespiratory fitness and exercise training on cerebrovascular blood flow and reactivity: a systematic review with meta-analyses.

We address two aims: Aim 1 (Fitness Review) compares the effect of higher cardiorespiratory fitness (CRF) (e.g., endurance athletes) with lower CRF (e.g., sedentary adults) on cerebrovascular outcomes, including middle cerebral artery velocity (MCAv), cerebrovascular reactivity and resistance, and global cerebral blood flow, as assessed by transcranial Doppler (TCD) or magnetic resonance imaging (MRI). Aim 2 (Exercise Training Review) determines the effect of exercise training on cerebrovascular outcomes. Systematic review of studies with meta-analyses where appropriate. Certainty of evidence was assessed by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Twenty studies (18 using TCD) met the eligibility criteria for Aim 1, and 14 studies (8 by TCD) were included for Aim 2. There was a significant effect of higher CRF compared with lower CRF on cerebrovascular resistance (effect size = -0.54, 95% confidence interval = -0.91 to -0.16) and cerebrovascular reactivity (0.98, 0.41-1.55). Studies including males only demonstrated a greater effect of higher CRF on cerebrovascular resistance than mixed or female studies (male only: -0.69, -1.06 to -0.32; mixed and female studies: 0.10, -0.28 to 0.49). Exercise training did not increase MCAv (0.05, -0.21 to 0.31) but showed a small nonsignificant improvement in cerebrovascular reactivity (0.60, -0.08 to 1.28; P = 0.09). Exercise training showed heterogeneous effects on regional but little effect on global cerebral blood flow as measured by MRI. High CRF positively effects cerebrovascular function, including decreased cerebrovascular resistance and increased cerebrovascular reactivity; however, global cerebral blood flow and MCAv are primarily unchanged following an exercise intervention in healthy and clinical populations.NEW & NOTEWORTHY Higher cardiorespiratory fitness is associated with lower cerebrovascular resistance and elevated cerebrovascular reactivity at rest. Only adults with a true-high fitness based on normative data exhibited elevated middle cerebral artery velocity. The positive effect of higher compared with lower cardiorespiratory fitness on resting cerebrovascular resistance was more evident in male-only studies when compared with mixed or female-only studies. A period of exercise training resulted in negligible changes in middle cerebral artery velocity and global cerebral blood flow, with potential for improvements in cerebrovascular reactivity.

The Effect of Cardiorespiratory Fitness and Insulin Resistance on Bone Health in Hispanic Children

Obesity appears to have a negative impact on pediatric bone health, and insulin resistance may mediate this relationship. It is unclear if cardiorespiratory fitness (CRF) has a protective effect on bone in obese children. We tested the hypothesis that CRF attenuates the negative effect of obesity and insulin resistance on skeletal health in a large cohort of Hispanic youth.We studied 413 (193 males and 220 females) children and adolescents from the Viva la Familia Study. They were all pubertal; mean age (SD) 13.4 ± 2.3 years; 27% were normal weight (NW), 19% overweight (OW) and 54% obese (OB). They underwent measurement of body composition, total body bone mineral content (BMC) and density (BMD) by DXA scan; VO2peak using the ramp protocol on a treadmill for CRF; fasting glucose and insulin. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. BMC increased from NW to OW to OB (mean 1.35 ± 0.4, 1.41 ± 0.4, and 1.49 ± 0.4 kg, respectively, p=.005). Peak VO2 decreased from NW to OW to OB (41.3 ± 9.7, 35.5 ± 7.7, 28.9. ± 5.5 mL/kg per min, respectively, p <.001). After adjusting for sex, age and lean body mass, BMC was inversely related to fat mass (r = -0.34, p <.001) and HOMA-IR (r = -0.29, p <.001). Similar relationships were found for BMD. In a regression model with BMC as the dependent variable, lean body mass (standardized coefficient (β)=0.95, p <.001) was positively and fat mass (β=-0.18, p <0.001) negatively associated with BMC (model R2=0.88, p<.001). HOMA-IR (β=-0.07, p =0.001) and VO2peak (β=0.09, p =0.003) had significant and opposite associations with BMC (model p<.001) but fat mass was no longer a significant contributor. With BMD as the dependent variable, lean body mass (β=0.82, p <.001), HOMA-IR (β=-0.06, p =0.04) and peak VO2 (β=0.17, p <.001), but not fat mass, contributed to the variance in BMD (R2=0.79, p<.001).In conclusion, lean body mass is the major determinant of BMC and BMD in Hispanic youth. Adiposity associated insulin resistance has a negative effect on BMC and BMD. CRF contributes positively to the variance in BMC and BMD. This suggests that CRF and higher lean mass attenuate the adverse effects of insulin resistance on bone health in children.

Abstract 13692: Cardiorespiratory Fitness and Atrial Fibrillation Risk in African American Veterans

Introduction: Atrial fibrillation (AF) is the most common sustained arrhythmia, affecting &gt;10 million in the USA. The beneficial effects of cardiorespiratory fitness (CRF) on cardiovascular (CV) diseases are well-documented. Interestingly, African American (AA) individuals are less prone to develop AF. Little is known about the association between CRF and AF in AA men. Hypothesis: CRF-AF risk association in AA men. Methods: We identified 11,216 AA Veterans with a mean age (±SD) 58±11 years who completed a symptom-limited exercise treadmill test at the VAMCs in Washington DC and Palo Alto CA. None exhibited evidence of ischemia or AF during and prior to it. We established four fitness groups based on age-specific quartiles of peak metabolic equivalents (METs) achieved: Least-Fit: 4.4 ±1.2 METs (n=2,530); Moderate-Fit: 6.6±1.3 METs (n=3,361); Fit: 8.1±1.4 METs (n=2,719) and High-Fit: 11.2±2.4 METs (n=2,606). AF was identified by a search of the medical records CPRS (database) using ICD coding and verified by 2 investigators. Cox proportional hazard models adjusted for age, CV disease, CV medications and risk factors were constructed to assess the CRF-AF association. P-values &lt;0.05 using two sided tests were considered statistically significant. Results: During a mean follow-up period of 10.7±6.2 years, 1,423 patients developed AF; 421(16.6%) in the Least-Fit, 366 (10.9%) in Moderate-Fit, 323 (11.9%) in Fit and 313 (12%) in the High-Fit group. The CRF-AF association was inverse and graded. When compared to the patients in the Least-Fit group, the AF risk in the Moderate-Fit group was 29% lower (HR=0.71; 95% CI: 0.62-0.82, p&lt;0.001). For Fit and High-Fit patients, the risk was 37% (HR=0.63; 95% CI: 0.54-0.73, p&lt;0.001) and 51.0% lower (HR=0.49; 95% CI: 0.42-0.57, p&lt;0.001), respectively. Conclusion: In this cohort, higher fitness levels reduced and delayed the risk of atrial fibrillation. The CRF-AF association was inverse, graded and independent of comorbidities.

The effect of cardiorespiratory fitness and physical activity levels on cognitive functions in survivors of childhood acute lymphoblastic leukemia

Introduction. Most childhood acute lymphoblastic leukemia (ALL) survivors develop chronic treatment-related adverse effects several years after the end of the treatment. Regular physical activity and a good cardiorespiratory fitness can decrease the risks of neurological disturbances and increase cognitive function scores. The aim of this study was to examine the effect of good cardiorespiratory fitness and physical activity levels on cognitive functions.Methods. We enrolled 219 survivors of childhood ALL. The participants underwent a cardiopulmonary exercise test, neuropsychological tests of executive functions (i.e. verbal fluency, cognitive flexibility, working memory, processing speed) and completed a physical activity questionnaire. We calculated the odds ratio to obtain the preventive fraction of physical activity and cardiorespiratory fitness levels on cognitive functions.Results. The cohort is 52% male and 48% female. A total of 182 survivors (83%) have a cardiorespiratory fitness below their predicted (<100%). Our analyses show that there is an association between good cardiorespiratory fitness and processing speed (preventive fraction of 70% for dominant hand (p < 0.01) and 65% for non-dominant hand (p < 0.01)) and with cognitive flexibility identified as the category switching measure of the D-KEFS verbal fluency (preventive fraction of 61%; p < 0.05).Conclusion. Good cardiorespiratory fitness and good levels of physical activity were associated to a preventive fraction for most cognitive function parameters measured. Good cardiorespiratory fitness levels were significantly associated with a lower prevalence of deficits in processing speed (i.e., dominant hand and non-dominant hand) and in cognitive flexibility (i.e., category switching) in childhood acute lymphoblastic leukemia survivors.

An Overview of the Cardiorespiratory Hypothesis and Its Potential Contribution to the Care of Neurodegenerative Disease in Africa

One hypothesis that could explain the beneficial effects of physical exercise on cognitive function is the cardiorespiratory hypothesis. This hypothesis proposes that improved cognitive functioning may be in part a result of the physiological processes that occur after physical exercise such as: Increased cerebral perfusion and regional cerebral blood flow. These processes ensure increased oxygenation and glucose transportation to the brain, which together can improve cognitive function. The objective of this narrative review is to examine the contribution of this hypothesis in the care of African older adults with neurodegenerative conditions (i.e., dementia (Alzheimer’s disease)) or with mild cognitive impairments. Although studies in developed countries have examined people of African descent (i.e., with African Americans), only the limited findings presented in this review reflect how these conditions are also important for the African continent. This review revealed that no studies have examined the effects of cardiorespiratory fitness on neurodegenerative disease in Africa. African nations, like many other developing countries, have an aging population that is growing and will face an increased risk of neurodegenerative declines. It is therefore imperative that new research projects be developed to explore the role of the cardiorespiratory fitness in neurodegenerative disease prevention in African nations.

Cardiorespiratory fitness and arm bone mineral health in young males with spinal cord injury: the mediator role of lean mass

ABSTRACTSpinal cord injury (SCI) derives in loss of bone mineral content (BMC) and bone mineral density (BMD). However, physical activity is an important determinant in bone mass acquisition, which is partially mediated through the lean mass (LM). The aim was to examine the effect of cardiorespiratory fitness (CRF) on BMD and BMC arms of adult males with SCI and able-bodied controls using the arm LM as a mediator variable. Thirty able-bodied men and thirty men with SCI participated. BMC and BMD were analysed by DXA, and indirect calorimetry was used to calculate VO2peak during a progressive arm-cranking test. When groups were divided by the amount of LM, the subgroup with highest LM had significantly higher arm BMC compared to the lowest LM subgroup (p ≤ 0.05) in both SCI and able-bodied groups. Moreover, same differences were found when confidence intervals were analysed. Only in the SCI group, arm LM mediated the relationship between bone mass and CRF at 30.9%, as indicated by the Sobel test (z = 2.17 and z = 2.04 for BMC and BMD, respectively). In conclusion, LM mediates the indirect association between CRF and bone health, specifically in the arms. This finding highlights the importance of having an adequate CRF for the maintenance of good bone health in SCI men.

Effect of Cardiorespiratory Fitness on Co-Morbidities and Mortality in Never, Past, and Current Smokers

Smoking is a strong risk factor for cardiovascular (CV) disease and mortality, but quitting may cause weight gain and increase the risk of co-morbidities. Our aim was to investigate the effect of smoking and exercise on weight-associated co-morbidities and mortality. We included Minnesota residents without baseline CV disease who underwent exercise testing from 1993 to 2010. Mortality was determined from Mayo Clinic records and Minnesota Death Index. Total, CV and cancer mortality by smoking status and cardiorespiratory fitness (CRF): (1) <80%, (2) 80% to 99%, (3) ≥100%. Differences were tested using logistic and Cox regression adjusting for age and gender. A total of 21,981 patients (7,090 past, 2,464 current smokers) were included. Past smokers had more obesity, hypertension, diabetes, and low CRF compared with never smokers. Current smokers did not show increased risk factor prevalence compared with never smokers but had higher rates of low CRF. There were 1,749 deaths; mean follow-up was 12 ± 5 years. Mortality was only slightly increased in past versus never smokers (Hazard Ratio: 1.2; 95% confidence interval 1.12 to 1.38) but was much higher in current smokers (Hazard Ratio 2.4; 95% confidence interval 2.05 to 2.80). Mortality in never, past, and current smokers was inversely related to CRF level. In conclusion, past smokers showed higher rates of co-morbidities and low CRF, but mortality was only mildly increased versus never smokers, whereas current smokers carried a high mortality risk. Our data suggest that quitting smoking is beneficial despite the increased co-morbidities. Exercise may potentially mitigate the risk of co-morbidities and death in those who quit smoking.

Effect of Cardiorespiratory Fitness on Risk of Sudden Cardiac Death in Overweight/Obese Men Aged 42 to 60 Years

The purpose of this study was to examine the subject and combined associations of cardiorespiratory fitness (fitness) and body mass index (BMI) with the risk of sudden cardiac death (SCD) in middle-aged men. This prospective study was based on a population sample of 2,357 men aged 42 to 60years, who were followed up in the Kuopio Ischemic Heart Disease cohort study. Fitness was directly measured by peak oxygen uptake (VO2peak) during progressive exercise testing to volitional fatigue. Participants were divided into 4 groups (fit-normal weight, unfit-normal weight, fit-overweight/obese, and unfit-overweight/obese) based on the median values of fitness and BMI. A total of 253 (10.7%) SCDs occurred during an average follow-up of 22years. After adjusting for potential confounders, the hazard ratio (HR) and 95% confidence interval (CI) for SCD was 1.80 (95% CI 1.21 to 2.68) for BMI ≥30.0 kg/m2 versus normal weight cohort, that is, BMI corresponding to 18.5 to 24.9 kg/m2. However, these associations were no longer statistically significant after adjusting for VO2peak (1.49, 95% CI 0.98 to 2.24). Compared with the lower levels of fitness, upper levels of fitness had a 39% lower risk of SCD (HR 0.61, 95% CI 0.40 to 0.92) after adjusting for potential confounders, including BMI. In the combined associations of fitness and BMI with the risk of SCD, unfit-overweight/obese men had 1.80times (95% CI 1.06 to 3.06) increased risk of SCD, but fit-overweight/obese men were not at increased risk of SCD (HR 1.22, 95% CI 0.66 to 2.25) as compared with their fit-normal weight counterparts. In conclusion, both overweight/obesity and fitness were independently associated with the risk of SCD; however, fitness appears to attenuate the risk of SCD in overweight/obese men, suggesting that improving fitness may reduce the risk of SCD in this population.